Balancing machine for propeller shafts



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Inutili-#|111 BALNCING MACHINE FOR PROPELLER SHAFTS July 16, 1935.

July 16, 1935. 'r` C, VAN DEGRlFT 2,008,161-

BALANCING MACHINE FOR PROPELLER SHAFTS Filed Feb.1o, 1930 4 sheets-sheet 2 @MZ @Mw @L July 16, 1935. r. c l VAN DEGRIFT 2,008,161 Y BALANCING MACHI-NE FOR PROPELLER SHAFTS Fileqeb. 10, 1950 4 sheets-sheet 5 gunna/tofs Mwf" July 16, 1935. T. c-vAN -DEGRn---r cog-.1

BALANCING MACHINE FOR PROPELLER SHAFT'S Patented July 16, 1935 PATENT' OFFICE naam ALANcmG moms: Foa raorELLEn nar'rs Thomas G. Van Delrift,

assignments, to General Motors Cor- Detroit, Mich., a corporation of by mcsne poration, Delaware Detroit, Mich., assigner,

Application February 1o, 1930, serial No. 427,259

16 Claims.

Although the present invention is referred to as a balancing machine for propeller shafts, it should be understood as applicable to the ascer- .tainment of unbalance in various substantially cylindrical or elongated elements or organizations o f the general character referred to; and it ls an. especial object of the invention to provide means for the testing of such elements at speeds and under conditions comparable with those -to which they are to be subjected in subsequent use.

This machine aims to provide means for the experimental production and study of whip, and also means for the ascertainment of both the angular location and the amount of any unbalance that, if unconected, would be likely toproduce such whip at an'y intended speed of opera ion.

It has only recently been recognized that propeller shafts, even though produced by modern means and methods, are liable to be so unbalanced, either statically or dynamically or both, as to produce a noisy and unpleasantwhip during rapid rotation-the location, directionV and amount of this whip varying not only with the local or general flexibility of the shaft (as resulting from its configuration, its method of production and/or the kind and amount of metal therein) but with the degree and nature of any ously indicating any net or virtual or resultant imbalance or whip at both ends of a shaft which is supported and rotated as if inl actual use; and, in preferred embodiments of the invention, one of the mentioned bearing shafts being provided with drive means such as a variable-speed motor flexibly coupled to one of the mentioned shafts (or to an intermediate shaft including a worm section from which an indicator Amirror may. be synchronously driven) one of' said shafts may also transmit motion to an. additional instrument, such as an electrical tachometer, for indicating the speed at which a particular vibration effect is observed.

Other objects of the present invention, including means for at times steadying or otherwise positioning the floating bearing shaft or shafts referred to, safety means and optionallyalso means to reduce the unbalance and thereby eliminate the whip of a shaft or other unit which has undergone test, may be best appreciated from the following description of an illustrative embodiment of said invention, taken in connection with the appended claims and the accompanying drawings.

Figure l is a side elevational general view, withfsomedetails omitted and showing only the upper portion of a rugged supporting bench or unbalance therein; and it is an object of this in- -bed vention to provide not only guidance to improved design and shaft production methods but also means which facilitate such a checking and/or balancing of each shaft in a shop production line as substantially to obviate any whip that might result from the causes last referred to.

It is a further object of this invention to provide a machine for ascertaining unbalance in which the propeller shaft or'v other unit undergoing test may beheld (in a horizontal or other position) in the general manner in its intended subsequent use; and, forthe testing of terminally flanged shafts or other units without endfor-end reversal, this invention may employ, at one or both ends of said umts, aanged bearing shaft or shafts supported by floating means. Said bearing shaftor shafts are thus -fnee to respond to any tendency of one or both ends of the shaft or unit to wobble or vibrate at moderate speeds, or to whip during rapid rotation; and the'movements referred to may be transmitted, by suitable pitman-like arms, foindicators of a type' heretofore described-in which a rotating mirror, a finger-shifted reflector and a fixed light are so assembled as to project a graph.

This machine provides means for simultane- Flgure 2 is a transverse section, taken substantially as indicated by the line 2-2 of Figure l, but on a somewhat enlarged scale.

Figure 3 is a longitudinal section, taken subl stantialiy as indicated by the line 3 3 of Figure 2.

Figure 4 is a transverse section, taken substantially as` indicated by the line 4 4 of Fig- 4ure 1 and showing a preferred type of floating bearings and means for transmitting motion therefrom to an indicator.

Figure 5 is a partial end elevation, taken substantialiy as indicated by the line 5-5 of Fig- Vlire 1.

Figure 6 is ationgitudinal sectional detail view, taken'from the direction indicated by the line l-I of Figure 5.

Figure 7 is a partial transverse sectional view showing, in side elevation and with parts broken away, a preferred type of indicator.

Figure 8 ispan elevational view, with parts broken away, taken substantially as indicated by the arrow l of Figure 7.

Figure 9 is a transverse sectional view, taken substantially as indicated' by the line 9?! of `Figure l and showing one available type of safety is shown as supporting, upon a common base plate I2, both an electric motor I3, preferably of a variable speed type, and a cating bearing organization I4. The latter may include a bearing shaft I5 and a flange I6,-suitable to engage a usual flange I1 upon one end of a propeller shaft I8 or other unit undergoing test. In proximity to the floating bearing organization I4, and optionally supported upon a subsidiary base element I9, is shown a so-called sine-wave indicator 2U; and, in preference to transmitting motionvdirectly from'a drive shaft 2I of motor I3 to the mentioned bearing shaft I5, a short shaft 22, carrying a worm 23, may advantageously be interposed, (by means such as a coupling 24 and a pair of universal joints 25 and 26,-one or more of the parts last referred to being such as to permit longitudinal play) in such manner as 'to provide for the rotation of sine-wave indicator drive shafts 21, 29 and 28' and/or the operation of a speed indicator through a drive shaft 29. This may be effected by means of gears 30 and 3l, engaging the Worm 23, and any requisite intermediate gearing, such as that suggested at 32, 32 Figure 2; and speed reduction in a ratio such as 8 to l may be incidentally effected between shafts 22 and 28.

To support that end of a shaft or unit I8 which is remote from the motor I3, in preference to providing a mere fixed-axis bearing or reversing the position of the unit to complete a test, a floating bearing organization I 4, including a bearing shaft I5' and a flange I6' may be employed,-any vibratory motion imparted to said bearing shaft being shown upon an indicator 20. This is shown as driven by an extension or part 23 of the mentioned indicator drive shaft 28; and the details of construction of the oatingr -bearing assemblies, as also those of any finger-shifting mechanisms interposed between bearing boxes 33 and the indicators 20, 20', may be substantially identical and of the general character suggested in Figures 4, 5, and 6.

In the figures last referred to, floating bearing organizations I4, I4' are shown as each including a substantially rectangular bearing box 33, containing bearings 34, 34 separated by spacers and heid by means comprising nuts; and the box 33 is shown as integrally or otherwise rigidly connected with an arm 36 and as supported by re'- silient means including a compression spring 35,--an -opposition spring 35' being optionally interposed above said box and below a horizontal upper portion of a bracket 31. The arm 36 is shown as provided at or near its end remote from box 33 with both an indicator actuating finger 33 and a transverse pivot pin 39; and one of the parts last mentioned may be connected with v some suitable restorative means, yieldably hold- `ing said box and parts therein against motion thereabove or therebelow, as at 4I, and provided with restorative means such as a pair of opposed compression springs 42 and 43. These may be set in depressions 44 and 45, oppositely provided in said link; and they may be outwardly engaged by stops 46 and 41. The upward pressure of the spring 35 or its equivalent may be adjusted by means vsuch as nuts 48 and 49; and comparable adjustment of the springs 42 and 43 may be effected by means such as nuts 5D and 5I upon a threaded rod 52,-shown as extending through brackets 53 and 54 and also loosely through the springs 42 and 43 and link 40,-the arm 36 functioning as a pitman.

It will be seen that the described construction is such that any merely vertical movement of the bearing shaft I5 or I5', due to a slight deficiency lor excess of weight in a unit I8, tends to produce only a corresponding rotative adjustment of the finger 38 upon the pin 39 so long as there is no lateral wobble or eccentric rotation of shaft I5 or, |5'; and thatany eccentric movement of the bearing shaft I5 or I5 tends to produce lateral movement of the entire finger 38, as a result of a reciprocation of the pin 39,--with a limited rotation of the link 4D upon its pivot 4I. 'The movement cyclically imparted by finger 38, through means such as a suitable ball or roller 55, to indicating parts within an indicator 2li, 20', will thus be seen to result from orbital displacement of the geometrical axis of bearing shaft I5'; and the correct interpretation of any graph traced by the indicator may accordingly depend upon proper synchronization of rotative movements and upon a proper initial positioning of the bearing shafts I5, I5'.

For the purpose last referred to, the bearing flange or flanges I6, I6 may be graduated in degrees and so set that the zero thereon corresponds to a base line on a graph-receiving indicator sheet or surface; and whatever radial plane of a shaft or unit undergoing test may happen to come opposite the zero on the flange or flanges I6, I 6' may be arbitrarily marked, and treated throughout subsequent operations, as the zerof radial plane, or plane of reference, of the said shaft or unit. For example, connections may be such that when the zeros on flanges occupy front positions, as at starting, reflected 4beams of light stripe the base lines of the indicators.

The base I9 of instrument 2U may be fixed, and

the base I9 of instrument 20 may be adjustable longitudinally of rails provided upon the bench I I, these parts being so rugged as not to participate in any vibrational movements herein referred to; and positioning of the instrument 20 and all parts movable with the base I9 will be understood to depend upon the length of a batch of shafts, or the like, in hand to undergo test.

The indicator or indicators 20, 20 may be substantially similar to those shown and described in my pending application S. N. 315,509, led October 27, 1928, except that shaft sections 28, 28 are herein shown as extending horizontally (this use of horizontal shafts being largely a matter of convenience) and as provided with longitudinal keyv ways,-to permit the adjustments above referred to; and the shaft 28 is shown as supported at intermediate points by means including bearings 56, 56,-such as may be advantageously provided upon a pair of safety devices 51, 51. These are shown as each including a curved guard part 58, pivoted at one end on a pin 59 and engageable at its opposite end by a retaining device 60; and the shafts 28, 28 are shown as also provided with bearings in the respective instrument housings,-

the mechanisms employed to rotate therefrom the shaft of a beam-reflecting mirror 2 l3 being modlis shown as engaging a lower horizontal element fled accordingly. v

As in the mentioned prior application, when intended to be used as described, indicator 26 and/or 20 may comprisewithin ahousing 226, not only the mentioned rotating or beam-reflecting mirror (whose sides or faces may correspond in number with a speed-reduction ratio between' shafts |5 and said mirror shaft, the illustrated mirror being octagonal in cross-section) but also an oscillatable concave mirror or finger-shifted reflector 22| (movable by any suitable indicator-actuatingV element, such as the mentioned nger 33), a light source 222, anclan arcuate window opening 223 having therein a suitable curved graph-receiving or graph-displaying translucent element 224,-a ray-restrictive element 225 and a background illumination window containing color-diffusion screen 226 being optionally provided in or carried by an inner wall or walls f226, defining a lamp compartment 229.

The curvature of the oscillatable mirror 22| is preferably such that an unvarying ray which it receives through an aperture 230 in the ray-restrictive element 225 (shown as retained in an and of such extent as to receive va straight or curved line of light corresponding, as to the period involved in its production, with a single revolution of the shaft 29, or with a single cycle in the' movement of the finger 33, or equivalent element,

.The lamp 222 may be rendered adjustable in any desired planes by means such as threaded elements 233, 233', 234, adapted tovserve as set screws and/or to extend through slots` such as that shownat 235 in a bracket 235. A door or pivot-supported section 236 of housing 223, optionally mounted upon hinges 231 at 'or near the center of the back of said housing, may provide for easy access to the lamp compartment and mentioned velements therein; and said compartment may be provided with any desired heatescape or Ventilating means,such as, for example, a stack 236, shown as provided with a screen 236.

Pivotaily to support the oscillatable mirror 22| for movement in a plane such as to assure continuousreilection from one or anotherof the reflecting surfaces of mirror 2|3 during each complete revolution of a spinning shaft -or any work unit undergoing test, and to render the oscillatable mirror 224 directly responsive to movements of some shiftable element such as nger 33 of a floating or other feeling organization, a forward extension 240 of housing. 226 being shown as interiorly provided with a shelf 24|, apertured at 242, a removable frame 243 yis .shown as interfitting within the aperture 242 and as carrying not onlyan inclined shaft 244 for 'mirror 22| but a vertical transmission shaft 245,-

Asaid shafts being interconnected by means of equal or unequal gears or gear sections 246, 241, and said transmission shaft being equipped vwith an adjustably carried roller-tipped multiplication lever or finger 246. A mentioned ball or roller 55 upon said finger may be retained in constant engagement with a suitable camsurface 38', near the end of finger 38,01, uponfahy' element used to transmit in oppositionfto a'sprin'g 253, the movements that are to b e observed. Said spring 25| of frame 243 and a mirror-receiving block 252; and a desired initial setting may `be facilitated by means such as set screws 253, 254, 255, and 253.

To facilitate insertion. and removal of the oscillating mirror frame 243 and/or the rotating mirror 2I3, an upper portion 251 of the indicator housing extension 243 may be separately formed and removable (as, upon the withdrawal of screws 253, shown as entering or engaging shelf 24|);

and the rotating mirror 2|! may be provided at its inner end with an interfltting part of a torquetransmitting coupling comprising elements 253 and L266,-the outer end of said mirror, or the shaft thereof, being shown as provided with a concave bearing element 26|, engageable by a spring-pressed bearing cone 262, which is slidably retainedV within a suitable thimble 233. Chromium plated stellite is regarded as superior to steel for use in providing a'true, highly reflective and permanent mirror 2|3; mentioned bearing elements, when separately formed, may

be secured in any preferred way,as, by a shrinking-on or by the use of binding screws 264 upon kerbed bearing elements; motion may be imparted to the bearing or coupling element 263, or its equivalent, by means such as an intermediate shaft section 265, shown as carried in a. bearing l266; and, incase rotary motion is to be transmitted thereto from one of the shaft sections 23. 23' any desired system of intermediatesears, and any suitable lubricating system, maybe employed within the 'housing 223, or within a subsidiary housing 261,-shown as provided with a remov- -able cover 263. y For example, the mentioned housing 261 and/or cover 266 may include bearings for/the shaft 233 of an idler gear 210, suitable forl the transmission of motion from a gear 21| on shaft 23 or 23' to a gear 212 on shaft 266; and bearing 266 may extend inward from a flat or plate 213, to which housing 261 and cover 263 may be secured by means such as screws'214. The door' vided with some .additional opening through V whichflnger 36 may upwardly extend as indicated in Fig. 7,; but the exact details of parts auch as those last referred to4 are obviously-ofv very.

minor importance herein,-being mentioned only for the sake of completeness of description.

As to operation, it will beunderstood that rotation of a reflecting surface of the mirror 2|3 is effective to produce, incidentally to the rotativevadvance of said reflecting surface and according to the rate of said rotation, the appear--A ance of an advancing spot or astraight or curved line of illumination upon the translucent element 224; and the distinctness of the eifect referred to may be enhanced by the use of the mentioned colored screen 226, to provide a diffuse illumination of green or other colored light,atfording a background upon which the mentioned line of indication is clearly visible.

-A complete or partial hood (not shown) may be provided thereover; and it will be understood that the translucent element 224 may be provided with any desired lines, graduations, legends or and the amount of any suoli excess (tending to displace the geometrical axis at one end of propeller shaft or like unit undergoing test, upon supporting and spinning the same in substantially the manner of its intended subsequent use, but so as to permit it to find its own axis of rotation) will be seen to be revealed by the deviation of a sine curve from a straight vertical line; and the indicators 20, 20 have accordingly been referred to as sine-wave indicators.

In order to obviate an end-for-end turning of any shaft assembly, to complete a test thereon, and in order to obtain simultaneous readings of simultaneous vibrations as the same may be modified-by interaction, in preferance to producing two graphs in different colors upon the face of a single instrument, separate instruments 2li, 2li are herein employed.

One of the bearing assemblies it, M' (or both of said assemblies, in case both are of floating type) may be provided with means to facilitate a centering of the bearing shaft or shafts l5, l, during insertion of a shaft or other work unit i8 and/or during the starting of the motor i3; and the means lastreferred to may advantageously be of such type as also to facilitate the initial positioning of the graduated flanges I6, It at zero or at any desired angle. For the purposes last referred to, a tubular extension 352 is shown in Figure 6 as adapted not only to contribute to the retention of mentioned bearings 34 within floating blocks 33 but to receive a portion. I5a of shaft I5,-`Whicl1 may be held concentrically therein by means including a gland organization 363; and the tubular extention 332 is shown in Figures 5 and 6 as including ratchetlike elements having cam surfacesradial tooth surface 365 thereon being adapted to engage cooperating ratchet-cam tooth surface 366 upon a manually manipulatable sleeve element 3151, and cam surface 363 upon said tubular extension being adapted to engage arcuate surfaces 339 in such manner as to hold the bearing shaft l5 or l5 centrally within the manually manipulatable element sleeve 331 when desired. The element,`

last referred to is shown as provided with an upwardly extending handle 313; and the relationship between the mentioned parts may be such that said handle may be used to ratchet" a ange i6 or it' to any position. When said handle is vertically disposed the graduated flange it or it may be, brought to zero (or to 120 or 240) The form shown in Figure 11 is similar to that just described but more rugged,-sleeve element 351e being duplicated at 351ml', and a horizontal handle 361:1 -being interposed between. radial handle elements 310e and 310e'. A single vertical spring' is employed at 35a, adjustable damping may be effected by means such as compressi.- ble annuli 31Ia surrounding pins 392 anden, and replacable cam screws or pins 333e are shown as adapted .externally to engage ratchetcam elements 368a, 368a' upon the ends of a` floating bearing box 33a, containing bearing shaft The propeller shaft I8 is shown as comprising, universal joints at 312 and 312 and a spline at 313, as well as the flanges I1, I1;v and it will be noted that positioning of the latter between flanges I6, I5 must dispose the same concentrically therewith. The power of the compression spring 35 or 35a is intended to be such that the weight of the-'mentioned coaxial elements and parts thereon, and the pressure of the spring 35', if employed, shall initially give the axis of bearing shafts I5, I5 a substantially central position, such as that illustrated in Figure 4,-or such as would occasion no movement of 'finger 33, by which an indicator 20, 20 is actuated; but any deviation of a work unit I8 from the central position referred to, or any deviation of a manually manipulatable element 361 or 361a or 351e' from a concentric position, is sucient to assure engagement of one or another of the teeth 335 for a zero-setting or other positioning effect, as above referred to; and such deviation may be effected by a momentary manual pressure upon shaft i8 or on a part secured thereto (or upon a handle 31@ or 310e', if sleeve element 361 or 351e and 351er are allowed some play).

Before or after the mentioned zero setting operation, the mentioned play-limiting element or elements 58 are intended to be brought to closed position, bymeans of handles 314'; and said elements may be advantageously provided not only with the mentioned retaining devices 60, including latch bolts adapted to extend through openings 315 in the free ends thereof, but with some means rendering the starting of the motor I3 conditional upon an additional voluntary act.

For example, `a slidable frame 315, supporting the safety devices, may support also a control organization 311, included within a circuit 318, 318', serving for the `energization of said motor upon the manipulation of any suitable speedvarying device such as is suggested at 319, Figure 1. The control device referred to may comprise resilient and curved terminal elements 380, 383', secured to the respective wires of the mentioned circuit and so disposed, near a bridging conductive element 38|, as to close a circuitk therethrough only when depressed; and depression thereof may be effected by means such as separate small plunger rods 382, 382', normally held elevated by means such as springs 383. Thus when a play-limiting guard element 58 is lowered into its latching position, entering within a keeper 33d through which a mentioned bolt of the latch organization Ell is movable, incidental depression of the rod 382, terminally provided with an cating R. P. M. are included in instruments 20,

2li', the speeds at which any vibrational effects occur may then be noted on an electrical or other tachometer 388, driven from some mentioned shaft-such as shaft (21, 28 or) 29.

- The general Inode of operation in the respective parts-comprised in the present invention having ybeen indicated in connection with the description thereof, it should be understood that, Whether or not means such as manually manipulatable elements 361 or 361a are so employed, in connection with one or more floating bearing assemblies, as momentarily to center the described bearing shaft or shafts while the motor I3 is speeding up, the said bearing shaft or shafts are to be left free to float during the actual test,- as by a shifting of handles 31|), 310', 31M to positions such as that shown in Figure 5; and the amount and location of any actual or virtual unbalance effecting either or both ends of the Work y 2,008,161 unit la (which win be seen to be termmny secured in substantially the same manner as if in actual use and whichl may be rotated at a speed such as that of normal use, or use under extreme conditions) will then be graphically indicated by a corresponding sinecurve or curves, upon the indicator or indicators 20, 20',-the positions and the dimensions of any lateral humps in the graphs being respectively indicative of the angular positions and the amounts'of any resultant unbalance or unbalances suflicient to cause vibration by eccentric movement or whip under the conditions referred to. For example, a central hump, extending halfway across one indicator sheet at (say) 1500 R. P. M. may imply a local or resultant excess of material correspondingto (say) two oz. in. at one end of the shaft I8 and at an angle of from the adopted zero radial plane thereon; and a hump of half this size located of the way up the other indicator face may then imply a local or resultant excess of material at theA other end of the shaft, corresponding to one oz. in. and at an angle of 270 from the same zero plane.

Although lcorrection of faults revealed in the above manner might obviously be affected by a removal or addition of material at points indicated, it is found that slight straightening or other bending operations aiord an expeditious, clean and convenient method of correction. Straightening may be effected and results thereof confirmed, if desired, `without removing the tested shafts or other units from the described machine; and the method here referred to is somewhat diagrammatically suggested by a showing, in Figures l, 9 and 10, of laterally shiftable wedges 389, optionally carried by the movbale frames 316 of safety devices 51, 51,said wedges and frames being adapted to sustain any corrective pressure applied through a hydraulic plunger 390 or the like, also laterally movable. It hasbeen found best in practice that the speeds where unbalanced readings are taken shouldA correspond to at least double the natural frequency of the spring supporting system. By thus operating above the resonance frequency of the spring supporting systeml greater accuracy is obtainable.

The foregoing description has included complete details of but one embodiment of the present invention; but itshould be understood not only that various features of said invention are capable of independent use but also'that numerous modiiicationsin detail might easily be devised,.

by workers skilled in the balancing art and familiar with the foregoing, without the slightest departure from the scope of the present invention.

Spring 35-35 and/cr spring 02--43 as well as the damping means 31Ia of Figure 11, are sometimes referred to in the claims as means for damping the orbital movement of the part to be balanced or its supports, since this is one of the functionsof the parts.

I claim: y l. In a balancing lmachine the combination of a pair of spaced members adapted to support beunbalance.

2. In a balancing machine the combination of a base, a link4 pivoted to the base, a second link pivoted to the first-named link, means yieldingly resisting turning movement of said links, a bearreceive a rotatable part to be tested for unbalance. means for rotating said part, means for indicating vibrational movement of one of said links due to unbalance of said part. a support adjacent said bearing,.and centering means carried by said support adapted to engage and center said bearing.

3. In a balancing machine the combination of a base, a link pivoted to the base, a second link pivoted to the rst-named link, means yieldlngly resisting turning movement of said links, a bearing associated with said second link adapted to receive a rotatable part to be tested for unbalance, means for rotating said part, a finger carried by one of said links, and an indicator means operated by said finger.

I 4. In a balancing machine the combination of a base, spaced links pivotally mounted on the base, links pivoted to the iirst named links, bearings associatcd with said second named links, means yieldingly resisting turning movement of said links, said bearings adapted to receive a rotatable part to be tested for balance, means for rotating said part, and meansfor indicating' vibrational movement of said part due to unbalance.

5. In a balancing machine the combination of a base, spaced links pivotally mounted on the ing associated with said second link adapted to base, links pivoted to the first-named links, bearsupports adjacent Lsaid bearings, and centering means carried by said supports adapted to engage and center said bearings.

6. In a balancing machine, the combination of f a base, spaced links pivotally mounted on the base, links pivoted to the first named links, bearings associated with said second named links, means yieldingly resisting turning movementy of said links, stub shaftsmounted in said bearings adapted to support between them a shaft to be balanced,

and means for rotating one of said stub shafts, and

means for indicating vibrational movement of said links due to unbalance.

7. In anorganization for ascertaining unbalance in a unit of propeller shaft type, spaced means for receiving the-ends of said unit and supporting it substantially as if in its intended use and providing a floating mounting therefor,

veach of said means comprising a pitman-like arm an'd a bearing for the unit associated with each arm, means for rotating the unit in said bearings, means for indicating unbalance, and means for transmitting movement from 4each of said spaced means to said indicating means to operate the latter.

8. In a balancing machine the combination of a base, a link pivoted on thebase, a second link pivoted to the first-named link, a bearing for a rotatable part associated with said second-named link, means for yieldingly resisting pivotal movement oi said links, means for-rotating a part to be balanced when mounted in said bearing whereupon the part, if out of balance, performs a yieldingly resisted orbital movement, and means operated by orbital movement of said part for indieating unbalance. i

9. In a balancing machine the combinationof a base, a pair of members movably connected to the base at spaced points, members pivotally connected to the first-named members, means for yieldingly resisting movement of said second namedv members, bearings associated with the second-named members adapted to receive and support between them a rotatable part to be balanced, means for rotating said part, said members permitting orbital movement of said part so as to assume a position of rotating balance, and means operated by orbital movement of said part for indicating unbalance thereof.

10. In a. balancing machine, the combination of a base, a pair of members movably connected to the base, members pivotally connected to the lrstnamed members, means for yieldingly resisting movement of said second-named members, bearf ings associated with said second-mentioned members adapted to receive and support between them a rotatable part to be balanced, means for rotating said part, said members permitting orbital movement of said part so as to assume a. position of rotating balance, means associated with each end of said part and operated by orbital movement of said part for indicating unbalance thereof, and means for locking either of said bearings against movement so as to obtain a reading of' out oi' balance of the opposite end of said part.

1l. In a balancing machine the combination of a plurality of spaced journal bearings adapted to receive in them the ends of the part to be balanced, means for supporting said bearings for independent orbital movement of revolution in parallel planes only, meansfor rotating a part mounted in said bearings, means for yielly resistingsaid orbital movement, and means operated by orbital movement of the bearing for indicating unbalance of a part under test. 12. In a balancing machine for jointed shafts and the like, the combination of spaced bearings adapted to receive the ends of a. shaft to be balanced, means for mounting each of said bearings so as to permit movement thereof in any direction in planes perpendicular to the axes of the bearings, and to prevent movement of the bearings in any other directions, means for yieldingly resisting movement of each of said bearings in said planes, means for driving a shaft when mounted in said bearings, and means operated by orbital movement of the Shaft for :lndieating unbalance thereof..

13. In a balancing machine for jointed shafts and the like, the combination of spaced bearings adapted to receive the ends of a shaft to be 'balanced, means for mounting each of said bearings so as to permit movement thereof in any direction in planes perpendicular to the axes of the bearings and to prevent movement of the wel: zV

ings many other directions, means for yieldingly resisting movement of said bearings in said planes, means for driving a shaft when mounty means yieldingly resisting movement of the Seond-named links, bearings for receiving the ends of the shaft to be balanced, associated with the second-named links, means for driving a shaft when mounted in said bearings, and means operated by orbital movement of the shaft for indicating imbalance thereof.

i5. In a balancing machine for jointed shafts and the like, the combination of spaced mountings adapted to be engaged with the ends of a shaft to be balanced so as to `permit rotation thereof, said mountings each comprising means permitting movement of the ends of the shaft in any direction in planes perpendicular to the airis'of the shaft and preventing movement thereof in any other direction, means associated with each of said mountings fcr yieldingly resisting movement of said ends in said planes, means for driving a shaft when engaged with said mountings, and means operated by' orbital movement of the shaft for indicating unbalance thereof.

i6. In a balancing machine for jointed shafts and the like, the combination of spaced mountings adapted to be engaged with the ends of a shaft to be balanced so as to permit rotation thereof, said mountings each comprising means permitting movement cf the ends of the shaft in any di-4 rection in planes perpendicular to the axis of the shaft and preventing movement thereof in any other direction, means associated with each of said mountings for yieldingly resisting movement of said ends ln said planes, means for driving a shaft when engaged with said mountings, means associated with each of said mountings and operated by orbital movement of said shaft in response to unbalance therein for indicating such imbalance, and means for locking either of said bearings against movement to permit reading of unbalance at one end of the shaft only.

THOMAS C. VAN DEGRIFT. 

